The NBA is now investigating the Philadelphia 76ers over their offseason dealings with James Harden, PJ Tucker and Danuel House.

According to Adrian Wojnarowski of ESPN, the league is looking at the possibility of the Sixers tampering on Harden. To recall, the superstar guard declined his $47 million player option with Philly and instead took less salary–a $15 million pay cut–to allow the team to sign Tucker and House.

However, some in the league believe that the Sixers and Harden have already agreed on a future deal, which is against the Collective Bargaining Agreement between the players and the NBA.

“The NBA has opened an investigation into the Philadelphia 76ers for possible tampering and early contact centered on franchise’s summer free agency class of James Harden, P.J. Tucker and Danuel House. Sixers have begun cooperating with league on probe,” Woj reported.

“NBA's expected to pursue circumstances surrounding Harden declining $47M option to sign a 1+1 deal that cut salary to $33M and gave team more flexibility to sign Tucker and House. Some have wondered if another deal was already in place for future — which is against CBA rules.”

If the Sixers were found to tamper on James Harden, they could be on the receiving end of a hefty punishment. Aside from the usual monetary penalty, teams found to be tampering can also get their draft picks taken away, or get their free agent signings voided. Suspension for the player is also in play, though rare.

It remains to be seen how the NBA plans to proceed with the investigation, but it could certainly be costly for the Sixers–one that could hinder their championship aspirations.